Ruth Hohl Borger, U of Florida Communications Specialist
LAKE ALFRED, Fla.—Americans' love affair with sugar can be a deadly attraction that sometimes leads to major health problems, including obesity and type 2 diabetes.
Finding natural, non-caloric sugar substitutes is desirable but challenging. However, researchers at the University of Florida Institute of Food and Agricultural Sciences have made a breakthrough — discovering new, natural sweeteners in citrus for the first time.
This finding opens opportunities for the food industry to produce food and beverages with lower sugar content and lower calories while maintaining sweetness and taste using natural products.
Yu Wang, associate professor of food science at UF/IFAS, managed the multi-year project that found eight new sweetener or sweetness-enhancing compounds in 11 citrus cultivars.
“We were able to identify a natural source for an artificial sweetener, oxime V, that had never been identified from any natural source previously,” said Wang, a faculty member at the UF/IFAS Citrus Research and Education Center in Lake Alfred, Florida. “This creates expanded opportunities for citrus growers and for breeding cultivars to be selected to obtain high yields of sweetener compounds.”
Replacing and reducing sugar in processed foods is a long-term goal of both the healthcare system and food and beverage industry. Consumers want a sweet-tasting orange juice, but they're also concerned about too much sugar consumption. Identifying the sweeteners and sweet-enhancing compounds could provide a solution for the “Sugar Bias” for the citrus industry.
To date, reducing sugar in food without compensating for sweetness can reduce the taste of most food. Replacing sugar with artificial, non-caloric sweeteners such as saccharin, sucralose and aspartame can negatively impact flavor profiles by leaving a bitter and metallic aftertaste. Consumers have shown increasing preference for naturally derived sweeteners that more closely resemble the sensory profile of sugar. To date, even natural, non-caloric sweeteners still possess some licorice-like and bitter aftertastes. While natural sweeteners are currently derived from fruits, some fruits are difficult to cultivate.
In addition to trying to find actual sweeteners in citrus, researchers looked to find sweetness enhancers that can significantly reduce the amount of sugar required to achieve the same level of perceived sweetness. To date, only six synthetic and two natural sweeteners/sweetness enhancers have been created and used by the food industry that are approved by the U.S. Food and Drug Administration. These also have the negative side effects of unpleasant aftertaste and are expensive to produce.
Eleven selections from the UF/IFAS citrus breeding program were selected for unique and exceptional flavors. These cultivars included UF 914 (a grapefruit hybrid), and EV-2 and OLL-20 (both sweet oranges). Mandarins, including Sugar Belle®, Bingo, 13-51, 18A-4-46, 18A-9-39, 18A-10-38, were also included in the research project.
Wang's research could lead to increased opportunities for the food industry to produce food and beverages with lower sugar content and calories while maintaining sweetness and taste using natural products, The research methodology also suggested that efficiencies of identifying flavor metabolites could be improved. This research was recently published in the Journal of Agricultural and Food Chemistry
And can you name these new sugars?
https://pubs.acs.org/doi/10.1021/acs.jafc.2c03515
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- Author: Ben Faber
TOPICS IN THIS ISSUE – P. Rolshausen Editor
- Mycorrhizae: An Underground Support Network for Trees.
- Notes on Applying Gibberellic Acid (GA3) to Navel Orange and other Citrus in the San Joaquin Valley of California
- Saline Waters - A Growing Problem
- 35th Anniversary of the Nematode Quarantine Facility at the University of California Riverside
- Author: Ben Faber
UC Riverside scientists are on the hunt for a chemical that disrupts “evil” weevils' mating and could prevent them from destroying California's supply of avocados.
Avocado weevils, small beetles with long snouts, drill through fruit to lay eggs. The weevil grubs or larvae bore into avocado seeds to feed, rendering everyone's favorite toast topping inedible.
“They're extremely hard to control because they spend most of their time deep inside the fruit, where they're very well protected from insecticides and natural enemies,” said UCR entomologist Mark Hoddle.
Not only are the insects reclusive, they are also understudied, making information about them hard to come by. “All books on avocado pest management will tell you these weevils are bad. They're well recognized, serious pests of avocados, but we know practically nothing about them,” Hoddle said.
One strategy for controlling pests is to introduce other insects that feed on them. However, that is unlikely to work in this case. “Natural enemies of these weevils seem to be extremely rare in areas where this pest is native,” Hoddle said.
To combat avocado weevils in Mexico, an area where they are native, and to prevent them from being accidentally introduced into California, Hoddle is working with Jocelyn Millar, a UCR insect pheromone expert. They are leading an effort to find the weevil's pheromone, with the goal of using it to monitor these pests and prevent them from mating in avocado orchards.
Pheromones are chemicals produced and released into the environment by an insect that can be “smelled” by others of its species, and affect their behavior.
“We could flood avocado orchards with so much pheromone that males and females can't find each other, and therefore can't reproduce,” Hoddle said. “This would reduce damage to fruit and enable growers to use less insecticides.”
Alternative control strategies could include mass trapping, using the pheromone as a lure, or an “attract-and-kill” approach, where the pheromone attracts the weevils to small sources of insecticide.
The work to identify, synthesize and test this pheromone in the field is supported by grants from the California Department of Food and Agriculture, as well as the California Avocado Commission.
An initial phase of the project sent Hoddle to a base of operations three hours south of Mexico City, an area with large weevil populations. Using a special permit issued by the USDA, Hoddle brought weevils back to UCR's Insectary and Quarantine facility.
Hoddle and Sean Halloran, a UCR entomology researcher, captured the chemicals that avocado weevils release into the air. Possible pheromone compound formulas were identified from these crude extracts and are now being synthesized in Millar's laboratory.
“Weevil pheromones have complicated structures. When they're made in a lab, they can have left- or right-handed forms,” said Hoddle. Initially, Millar's group made a mixture of both forms to see if the blend would work as an attractant, as it is far cheaper to make the blend than the individual left- or right-handed forms.
Field work in Mexico with the pheromone cocktail by Hoddle, his wife Christina Hoddle, an associate specialist in entomology, and Mexican collaborators did not get a big response from the weevils, suggesting that one of the forms in the blend could be antagonizing the response to the other.
As the next step, the researchers plan to synthesize the individual forms of the chemicals and test the insects' response to each in Mexican avocado orchards.
Because the levels of avocado imports from Mexico are increasing, the risk of an accidental weevil invasion is rising as well. Hoddle is hopeful that the pheromone will be successfully identified and used to lower the risk this pest presents to California's avocado growers.
“We've been fortunate enough to be awarded these grants, so our work can be implemented in Mexico and benefit California at the same time,” Hoddle said. “The tools we develop now can be used to make sure crops from any exporting country are much safer to import into California.”
/span>/h4>- Author: Ben Faber
Pollinators are essential to many of California's agricultural crops and to the vast biodiversity of California's natural ecosystems. Unfortunately, due to a variety of factors including habitat destruction, pesticides, disease, and climate change pollinators are in decline. The loss of pollinators in California affects both agricultural and natural ecosystems. It is the goal of the Pollinator Habitat Program to help strengthen pollinator populations and health.
The Pollinator Habitat Program was established by the Budget Act of 2021 (Senate Bill 170, Skinner). An allocation of $15 million to CDFA was made for fiscal year 2021-2022 to provide grant funding for the establishment of pollinator habitat on agricultural lands throughout California. CDFA was directed to administer the Pollinator Habitat Program and to prioritize the planning of native habitats for the benefit of native biodiversity and the use of locally appropriate native plant seed mixes when feasible.
The Pollinator Habitat Program will provide up to $14.5 million in funding to established and experienced organizations (See Eligibility) to work directly with farmers and ranchers to install habitat and implement management practices that support pollinators.
The Pollinator Habitat Program is aligned with the suite of Climate Smart Agriculture incentive programs administered by CDFA's Office of Environmental Farming and Innovation. The program's primary objective is to support pollinators through provision of floral resources, host plants and other elements of suitable habitat. Projects funded through the PHP can be expected to have additional benefits to California's biodiversity and agricultural production. Projects will support integrated pest management, support beneficial species (beyond pollinators), enhance carbon sequestration and improve soil health among other co-benefits.
The Pollinator Partnership — a non-profit 501 c3 dedicated to promoting the health of pollinators through conservation, education, and research — is conducting a survey to learn about California growers' preferences for on-farm conservation programs.
The voluntary survey, under contract for the USDA, is open to current owners and/or managers of farmlands in California, and should take about 10 minutes to complete.
Participants can take part in the survey regardless of past participation in a USDA conservation program. Responses will not identify participants individually; results will be aggregated and anonymized when presented.
All participants who complete this survey will be included in a raffle to win one of ten (10) $50 VISA gift cards. To be included in the raffle simply provide your email at the end of the survey.
Questions about this survey can be directed to (jordan@pollinator.org) or Vicki Wojcik (vw@pollinator.org) at Pollinator Partnership.
Click on this link to participate in the survey.